The objective of this study was to evaluate the effect of castration on dimensions of the prostate by B‐mode ultrasound for 90 days, as well as to evaluate changes in serum concentrations of testosterone and oestradiol in clinically healthy canines and those with benign prostatic hyperplasia (BPH). Three groups of animals were used: healthy canines castrated on day 0 (HCC, n = 8), canines with a diagnosis of benign prostatic hyperplasia (BPHC, n = 9) castrated on day 0 and healthy uncastrated canines (IHCC, n = 10). Prostate size was obtained by B‐mode ultrasound, while blood samples were collected (days 0, 7, 14, 28, 60 and 90 post‐castration) to determine the serum testosterone and oestradiol concentration. Castration did not affect serum oestradiol concentrations. Castration led to a decrease in serum testosterone (reaching values <20 ng/dl in the first week, p < .05), causing a gradual decrease in dimensions of prostate parameters relative to body weight (p < .05). Canines with BPHC had similar prostate dimensions as the IHCC group 2 weeks post‐castration. In relation to the prostate's relative parameters, the decrease with time was greater in canines with BPHC than those in the HCC group. When evaluating parameters as a percentage of relative change, the decrease with time was similar in both castrated groups, except for relative length percentage, which presented a more pronounced decline in BPHC canines than HCC canines. In conclusion, castration is an effective, fast and long‐lasting treatment for canine patients with BPH, as it causes a rapid decrease in blood testosterone concentrations and a decrease in glandular volume, but does not affect serum oestradiol concentrations. This study did not determine the mechanisms of action, but allowed us to observe (based on morphometric variables) that characteristics of prostate involution after castration differed between canines with BPH and healthy canines.

Objectives The aim of this study was to estimate the prevalence of hypersomatotropism (HST) and hyperthyroidism in cats with diabetes mellitus (DM) from referral centers in Buenos Aires, Argentina. Methods This was a prospective study. Systematic screening of serum insulin-like growth factor 1 (IGF-1) and total thyroxine was performed in all cats diagnosed with DM at referral centers in Buenos Aires between February 2020 and February 2022. Results In total, 154 diabetic cats were evaluated (99 males and 55 females; median age 12 years [range 3–21]; mean body weight 5 kg [range 2–12]). Altogether, there were 115 (75%) domestic shorthairs and one domestic longhair; the remaining 38 cats were purebred (mainly Siamese, n = 25 [16%]). Twenty (12.9%) cats had IGF-1 concentrations >1000 ng/ml, and three (1.9%) had IGF-1 concentrations between 800 and 1000 ng/ml along with pituitary enlargement on CT, resulting in a 14.9% HST prevalence rate in diabetic cats. Intracranial imaging was performed in all cats with HST; median pituitary dorsoventral height was 5.8 mm (range 3.1–9.5). Fourteen of 23 (61%) cats had phenotypic changes consistent with acromegaly at the time of diagnosis of HST. Four of 154 (2.5%) cats had concurrent hyperthyroidism. Conclusions and relevance To date, this is the first study outside of Europe to have evaluated the prevalence of HST and hyperthyroidism in cats with DM. In Buenos Aires referral centers, feline HST is the most common concurrent endocrinopathy in cats with DM but with a lower prevalence than has previously been reported. Hyperthyroidism is a rare concurrent endocrinopathy in diabetic cats from referral centers in Buenos Aires.